This invention pertains to voice over Internet protocol (VoIP) telephony. More particularly, this invention pertains to a particular artifact of VoIP telephony, which also provides customized ring back tone (CRBT) service, such as the CRBT service described in the inventor's issued U.S. Pat. No. 7,136,679.
FIG. 1 shows a simplified depiction of how voice over Internet protocol or VOIP occurs. A calling party 10 communicates with a called party 12 over a packet data network such as the Internet 14, by having pathways in each direction 16 by a proxy server 18. The pathways are “assigned” by assigning IP addresses to the data packets, the IP addresses designating a route through the network. The pathway is “assigned” during a set-up time, during which “signaling” messages 20 are exchanged between the proxy server 18 and the calling party 10 and between the proxy server 18 and the called party 12. After the proxy server receives “signaling” data 20 from the calling party 10, the proxy server 18 sets up, i.e., designates, a pathway through the network to the called party 12 by data “signaling” messages 22 that are also sent to the called party 12.
The inventor's issued U.S. Pat. No. 7,136,679 describes customized ring back tone (CRBT) service. FIG. 2 is a simplified depiction of how customized ring back tone service is provided in conjunction with VoIP telephone service. When a calling party 12 places a call to a called party 12, the calling party 10 hears a customized ring back tone instead of an ordinary ring back tone. The ring back tone (or perhaps a message) can be selected or generated by the called party 12. Music or messages, for example, can be sent from the customized ring back tone service server 24, over a pathway 26 through the network 1 to the calling party with the path between the server 24 and the calling party 10 set up through the network 1 by the proxy server 18.
A problem with VoIP that also provides customized to ring back tone service offered through an Internet protocol network is that a talk or “communications” pathway, i.e., a pathway from the called party 12 to the calling party 10 can take a considerable amount of time to set up. With VoIP that provides customized ring back tone service, when the called party 12 answers an incoming call ringing signal, the called phone will be silent to its user until a pathway is established through the network 1, leaving the phone's user wondering why the phone rang.